1. Field
The disclosed embodiments relate to the field of airplane piloting assistance. More particularly, the invention relates to a method and a device for improving the piloting quality and the safety of the airplane during the final phase of a flight with a view to a landing by providing the pilots with information enabling them to decide on whether to continue or interrupt a landing procedure.
2. Brief Description of Related Developments
The final flight phase of an airplane normally breaks down into three phases:
an approach phase, during which the airplane approaches the runway,
a leveling-off phase ending with the airplane touching down on the ground, and
an airplane taxiing phase on the runway.
The final flight phase is a difficult phase from a piloting point of view. A large proportion of all incidents occurs on landing. Among the incidents that can occur, longitudinal departures of the airplane from the runway are frequently observed.
These incidents on landing pose safety problems for the airplane and its occupants but also for the other users of the airport, and generate air traffic level difficulties involving delays, diversions. Even in the most minimal cases, following a runway departure, the airplane must be grounded for a detailed inspection and any repairs, for example a replacement of the landing gear. Furthermore, even without any impact on safety or on the integrity of the airplane, such incidents are ill-perceived by the passengers and affect the image of the manufacturer and of the operator of the airplane.
These incidents can more often than not be explained by the combination of several aggravating factors which degrade performance levels on landing, such as, for example:
the state of the runway (wet, covered with snow, etc.),
the presence of unfavorable wind, mainly a tail wind,
an inappropriate leveling-off piloting technique that can involve the wheels touching down a long way after the runway threshold,
a sequence of braking actions that is too slow or delayed.
Each unfavorable factor and their accumulations can culminate in a reduction of the safety margin of the airplane on landing, even a negative margin. In practice, it is not easy for the crew to fairly estimate the actual safety margin regarding the risk of longitudinal departure from the runway, because of the difficulty in assessing distances when the height is low. However, if the crew had had a better awareness of the situation relative to the safety margin during the approach phase, in many cases, it would have been able to decide on a go-around and incidents could have been avoided.
The U.S. patent published under the U.S. Pat. No. 7,068,187 proposes a method for assisting the crew of an airplane in a go-around decision. Many parameters, such as, for example, the deceleration required to stop the airplane on the runway after the wheels have touched down, the wind conditions on the runway, or the speed of the airplane, etc. are monitored during the approach phase in order to detect the conditions leading to a possible runway departure, and a risk level is assessed. When the risk exceeds a certain threshold, an alert is given to warn the crew of a need for a go-around.
However, the method described in this patent does not enable the crew to estimate the maneuvering margin at any instant and the speed of the actions to be completed after the wheels of the airplane touch down in order to enable said airplane to stop on the runway.
There is therefore an interest in informing the crew as early as possible as to the possibility or impossibility of landing on a runway and the speed with which the actions after the wheels touch down must be performed in order to guarantee that the airplane will stop before the end of the runway.